Preface
Today, I will share with you the interview experience of the group of friends in Dachang, and summarize the rules of Dachang interview for everyone
Alibaba Java job (three aspects of technology)
one side
1. Introduce yourself, talk about your job-hunting intention and skills
2. What is the basic architecture of Tomcat?
3. JVM tuning, how to use it at work, what are the GC algorithms and recycling strategies
4. How is the thread pool implemented in Java? What are the core construction parameters for creating a thread pool?
5. What is the difference between Volatile and Synchronize?
6. What is the mechanism of GC? Is the basic principle of the garbage collector still talking about it? Can the memory be reclaimed immediately? How to actively notify the JVM for garbage collection?
7. The parent delegation model mechanism of the class loader?
8. Types and differences of collections, how to implement the bottom layer of HashMap (with changes in JDK1.8), and the difference between HashMap and ConcurrentHashMap?
9. How does Spring IOC manage the dependencies between Beans and how to avoid circular dependencies?
10. What are the design patterns in the creation of SpringBean?
Two sides
1. Self-introduction,
2. What are the names of the four transaction isolation levels supported by InnoDB? What is the difference between?
3. Talk about the characteristics of business
4. What is the MySQL isolation level?
5. How to understand the BTree mechanism?
6. Talk about the analysis of slow queries? What are the optimization methods commonly used in MySQL?
7. Talk about the realization of pessimistic lock and optimistic lock and SQL
8. Briefly describe the three-way handshake and four-way handshake process?
9. What is the difference between B+ tree index and Hash index?
Three sides
1. Introduction
2. MySQL lock concurrency?
3. How to prevent deadlock and ensure data consistency in high concurrency scenarios?
4. Algorithm and implementation of clustering and load balancing?
5. Briefly describe the sub-library and sub-meter design?
6. What are the distributed dilemmas brought by sub-databases and sub-tables and corresponding strategies?
7. What is the locking mechanism?
8. How do Redis and Setnx commands implement distributed locks? How to use Redis for asynchronous queue? What are the disadvantages?
Tencent Java job (technical four sides)
one side
1. Tell me about your understanding of JVM?
2. The difference between treemap and HashMap?
3. The five states of multithreading?
4. What is the difference between MySQL primary key and index?
5. Talk about some projects done
6. How to realize session sharing? How to achieve this with Redis?
7. The concept and solution of cache breakdown?
8. Talk about microservices and how they are managed
Two sides
1. What is the difference between nio and io in Java? What are the commonly used classes?
2. Do you understand synchronization locks in Java? What is the difference between CountDownLaunch and Cylicbarrior and in what scenarios?
3. Which of the JVM memory structures are shared and which are thread private? What are the stacks stored in the Java virtual machine?
4. How to implement a thread pool?
5. Under what circumstances will Java class loading be triggered?
6. Handwritten code: quick sort, simple interest mode, draw a UML class diagram of factory mode and decorator mode
7. The realization principle of AOP
8. How to optimize slow queries?
9. What are the locks in Java? The difference between reentrant lock and non-reentrant lock?
10. What is the difference between Lock and Synchronized? Are they all reentrant locks? Which is more efficient?
11. The general realization of handwritten SpringMVC DispatcherServlet?
Three sides
1. Talk about the usual project concurrency experience
2. Data structure of Redis? Thread model? Redis's data elimination mechanism?
3. Have you read the source code of Redis?
4. The principle of MySQL implementation of transactions
5. The realization of the underlying principles of MQ?
6, database transaction acid, transaction operation, how to lock? Distributed system lock?
7. Under what circumstances will avalanches occur? How to solve?
All sides
1. Introduce some concurrent projects
2. For projects with high technical content, I asked again from architecture design to deployment
3. Design ideas for high concurrency architecture
Ant Financial's Java Position (Three Technical Aspects)
one side
1、HashMap和ConcurrentHashMap
2. Talk about the consensus algorithm of Hash
3. Optimistic and pessimistic locking
4. Reentrant lock and Synchronized
5. Four characteristics of business?
6. The two-stage commit mechanism of the transaction?
7, clustered index and non-clustered index
8. For example, what are the application scenarios and precautions of indexing?
9. Current read and snapshot read
10. Talk about the process of class loading?
11. Parental delegation mechanism and the reasons for its use?
12. Talk about the GC algorithm?
13. What is the difference between Http and Https? And the way of Https encryption
14. The core parameters and basic principles of the thread pool? Thread pool tuning strategy
15. Talk about personal career planning
Two sides
1. Talk about the projects you have done. What difficulties have you encountered?
2. How to sort the bottom of Collections.sort?
3. Stability of sorting, and sorting strategies in different scenarios
4. Http request process, DNS resolution process
5. Three-way handshake and four-way handshake
6. Briefly describe the thread pools and concurrency tools,
7, the index and principle of the database
8. How to analyze and solve the frequent recycling of old age?
9. Spring IOC/AOP related knowledge
10. Tell me about some applications of SpringBoot and SpringCloud?
11. How to implement blocking queue without Java?
12. The principle of load balancing?
13. Redis data consistency issues, described separately in distributed multi-node and single-node environments
14. Talk about Docker containers
15. How to achieve peak shaving and current limiting in a high concurrency environment?
Three sides
1. Talk about the middleware used in the project (Dubbo/MQ/Zookeeper/Redis/Kafka)
2. Under what circumstances will avalanches occur? How to avoid this situation
3. Design ideas for high concurrency architecture
4. Talk about problems encountered in previous projects and solutions
5. What setbacks have you encountered in your life? How to solve it in the end
6. The most fulfilling thing encountered in life?
to sum up:
Through these interview experiences, it is not difficult to find that first-line Internet companies pay more attention to the ability to solve problems in actual projects . In addition, the knowledge points of the interview mainly revolve around JVM , multithreading , basic knowledge of the underlying principles , performance tuning , source code reading ability , Ability to handle high concurrency .
Next, the editor prepared the answers to the above interview questions for everyone, and the corresponding interview question materials to receive: Click here to receive it for free, the code: CSDN
